Sinkhole risk in Montgomery County, OH: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 100%
At or near the surface: 0%
Buried under cover: 100%

The next step for one property

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 461 of Montgomery County's 461 square miles on soluble rock. With about 537,443 residents (1,165 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 342 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 100% under cover still counts, and the signs to look for and how an inspection works.

Counties around Montgomery County

The nearest county rated sinkhole country is Kenton County, KY, about 58 miles south. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Preble County, OH 19 mi west · 0% at surface
Miami County, OH 21 mi north · 0% at surface
Greene County, OH 22 mi east · 0% at surface
Warren County, OH 24 mi south · 0% at surface
Butler County, OH 26 mi southwest · 0% at surface
Clark County, OH 29 mi northeast · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Drakes, Whitewater and Liberty Formations, Undivided (shale), Ordovician in age, covering about 25% of the county. Next is the Grant Lake and Fairview Formations, Miamitown Shale, Undivided at 16%.

Against the rest of Ohio

Montgomery County ranks 58 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.